Implement retainer



Patented Mar. 25, 1941 UNITED STATES PATENT OFFICE IMPLEMENT RETAINER Grover G. Tuttle, Phillipsburg, N. J., assignor to Ingersoll-Rand Company, Jersey City, N. J., a corporation of New Jersey This invention relates to rock drills, and more particularly to implement retainers for rock drills of the hammer type in which the working implement is capable of free reciprocatory movement with respect to the hammer piston whereby it is actuated.

One object of the invention is to enable the retainer to be quickly moved into and out of the retaining position.

Another object is to equip the rock drill with a rugged retainer capable of withstanding the severe usage to which devices of this character are subjected and which may be readily replaced with a minimum of expense.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawing accompanying this specification and in which similar reference numerals refer to similar parts,

Figure 1 is an elevation, partly in section, of the front end of a rock drill and a retainer constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken through Figure 1 on the line 2-2 looking in the direction indicated by the arrows, and

Figure 3 is a side elevation, partly broken away, of the rock drill and the retainer.

Referring more particularly to the drawing, 20 denotes a front head of a rock drill or percussive tool and 2i a bore in the front head. The bore 2! comprises a forward portion 22 of reduced diameter and a rearward enlarged portion 23 and contains a bushing 24 which is bored to receive the shank 25 of a working implement 25.

A hammer piston 2'! is shown extending in the bushing 24 to deliver blows against the shank 25 and at the juncture of the shank 25 with the body portion of the working implement 26 is a collar 28 that abuts the front end of the bushing 24 to limit the distance which the working implement may extend into the rock drill.

The collar 28 lies in the forward end of the reduced portion 22 of the bore and is normally retained therein by the retainer 29 which, in accordance with the practice of the invention, is arranged immediately adjacent the front end of the front head. The retainer is in the form of a cylindrical member having a flange 30 which lies in a recess 3| in the end of a cap 32 seated against the front end of the front head 20 to which it is secured by bolts 33.

The retainer 29 is of such length that a portion 34 thereof extends exteriorly of the lower or front end of the cap 32 and the surface of the portion 34 is roughened, as by knurling, to provide a'suitable grip portion which may be grasped with the hand for rotating the retainer.

The retainer 29, in the present instance, entirely encircles the body portion of the working implement 26, and the aperture 35 in the retainer through which the working implement extends loosely is arranged eccentrically with respect to the periphery of the retainer so that, in what may be termed the retaining position of the retainer, a portion thereof defining the aperture 35 will lie in the path of the collar 28 to act as an abutment therefor.

To the end that upon rotation of the retainer in the cap 32 the aperture 35 may be brought into 1 coaxial alignment with the collar 28, so that the collar may readily pass through the retainer, the bore 35 in the cap 32 through which the reduced portion 34 of the retainer extends is also arranged eccentrically with respect to the bore 2|. by the foregoing described arrangement the retainer may be placed in a position in which the aperture 35 will be out of axial alignment with the working implement and a portion of the rear end of the retainer will then lie in the longitudi- I nal plane of the collar 28. Whenever it is desired to remove the working implement the retainer is rotated to another position, as for example through an arc of 180 from the retaining position, and in this way the aperture 35 will be ample by spring-pressed plungers 3'1 arranged in sockets 38 in the front head to engage depressions 39 in the innermost end of the retainer 29.

I claim:

1. In an implement retainer for percussive tools, the combination of a front head and a working implement in the front head adapted to be reciprocated and having a collar, a cap on the front head having a bore to receive the working implement and said bore being arranged eccentrically with respect to the working implement, and a retainer in the bore loosely encircling the Working implement and having a second bore arranged eccentrically therein, said retainer being rotatable in the bore to different positions to lie in the path of the collar and to bring the second bore into coaxial alignment with the collar.

2. In an implement retainer for percussive tools, the combination of a front head and a working implement in the front head adapted to be reciprocated and having a collar, a cap on the front Thus,

head having a bore to receive the working implement and said bore being arranged eccentrical- 1y with respect to the working implement, a retainer in the bore loosely encircling the working implement and having a second bore arranged eccentrically therein, said retainer being rotatable in the bore to different positions to lie in the path of the collar and to bring the second bore into coaxial alignment with the collar, a gripping member on the retainer extending exteriorly of the cap for rotating the retainer, and means for holding the retainer in retaining and non-retaining positions.

3. In an implement retainer for percussive tools, the combination of a bored front head and a working implement in the front head adapted to be reciprocated and having a. collar, a cap having a recess and a second bore arranged eccentrically with respect to the front head bore to receive the working implement, bolts to secure the cap to the front head, a cylindrical retainin member in the second bore having a third bore eccentrically located with respect to the front head bore and loosely encircling the working implement, a flange on the retaining member to lie in the cap recess, said retaining member being rotatable in said second bore to different positions to lie in the path of the collar and to bring the third bore into coaxial alignment with the collar, a knurled gripping member on the retaining member extending exteriorly of the cap for rotating the retainer, depressions formed on the retaining member, and spring pressed plungers'in the front head to engage the depressions and hold the retaining member in any one of several operative positions.

GROVER G. TUTTLE. 

